The present invention relates to data monitoring and management systems. More specifically, the present invention relates to method and apparatus for providing leak detection in sensors used in data monitoring systems such as glucose monitoring systems.
Glucose monitoring systems including continuous and discrete monitoring systems generally include a small, lightweight battery powered and microprocessor controlled system which is configured to detect signals proportional to the corresponding measured glucose levels using an electrometer, and radio frequency (RF) signals to transmit the collected data. One aspect of such glucose monitoring systems include a sensor configuration which is, for example, mounted on the skin of a subject whose glucose level is to be monitored. The sensor cell may use a three-electrode (work, reference and counter electrodes) configuration driven by a controlled potential (potentiostat) analog circuit connected through a contact system.
The current level detected by the work electrode of the sensor is relatively small such that even a small amount of leakage current from the reference or counter electrodes typically will affect the signal quality, and thus may have adverse effect upon the accuracy of the measured glucose level. This is especially true when foreign matter is present that causes a false high glucose reading, and which may lead to improper patient treatment. Furthermore, when the glucose monitoring system is calibrated, the offset and gain of the sensor-transmitter pair is established. If the leakage current level changes (i.e., either increases or decreases), then the offset established will likely change and a resulting gain error may result for future calibration points.
In view of the foregoing, it would be desirable to have an approach to detect leakage current in sensor configuration of data monitoring systems such as in glucose monitoring systems such that detective sensors resulting from leakage current may be identified that are not detecting signals accurately.